/* 
 * [New BSD License (BSD 3-Clause License)]
 * Copyright (c) 2012, Max Bechtold
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 *     - Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     - Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     - Neither the name of the Rel2Xml Project nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package maxbe.rel2xml.generator.dml;

import java.util.ArrayList;
import java.util.List;

import maxbe.rel2xml.grammar.TranslateDmlException;

import org.apache.log4j.Logger;

public class OrderBy implements Clause {

	private Logger log = Logger.getLogger(OrderBy.class);

	private final List<ResultColumn> columns;

	private Query query;

	public OrderBy() {
		columns = new ArrayList<ResultColumn>();
	}

	public OrderBy(List<ResultColumn> columns) {
		this.columns = columns;
	}

	public List<ResultColumn> getColumns() {
		return columns;
	}

	public void setQuery(Query query) {
		this.query = query;
	}

	public void addColumn(ResultColumn column) {
		if (columns.contains(column)) {
			String msg = String.format(
					"Column '%s' is already listed in order by clause.",
					column.getName());
			log.error(msg);
			throw (new TranslateDmlException(msg));
		}
		columns.add(column);
	}

	@Override
	public String toXQuery() {
		String order = "";
		for (ResultColumn col : columns) {
			if (!order.isEmpty())
				order += ", ";
			order += String.format("$%s/%s %s", col.getEntity().getAlias(), col
					.getXmlName(), (col.isOrderedAscendant() ? "ascending"
					: "descending"));
		}
		return "order by " + order;
	}

	@Override
	public String toSql() {
		String order = "";
		for (ResultColumn col : columns) {
			if (!order.isEmpty())
				order += ", ";
			order += col.getName()
					+ (col.isOrderedAscendant() ? " asc" : " desc");
		}
		return "order by " + order;
	}

	@Override
	public String toString() {
		return toSql();
	}

	public boolean determinesOrder(Entity entity) {
		if (query.getOrderBy() == null)
			return false;
		for (ResultColumn column : query.getOrderBy().getColumns())
			if (column.getEntity() == entity)
				return true;
		for (Entity child : entity.getChildren())
			if (determinesOrder(child))
				return true;
		return false;
	}

}
